I took everything apart but I am not good at identifying circuit components but I suspected things would be easier to diagnose and repair or replace with a litt

I took everything apart but I am not good at identifying circuit components but I suspected things would be easier to diagnose and repair or replace with a little more open info from the manufacturer but that is unlikely. Knowing how to repair a prelit tree is key to designing a repairable prelit tree. So to me, your first hurdle toward making what you are talking about would be learning to use a soldering iron, multi-meter, micro-controller programming to a level that you can fix a tree like yours without manufacturer support. To me, that sounds like a lot of work over a non-trivial time window. Which is to say, the difficulty of making what you are thinking of is non-trivial. But that's almost always the answer to "How hard could it be?" ideas. Yes, there are people for whom it would be of little difficulty. Those people would not need to ask because they would know how hard it would be and it would only be a choice of if it was worth the bother. Good luck.